Much of the ongoing research in ubiquitous computing has concentrated on providing context information, e.g. location information, to the level of services and applications. Typically, mobile clients obtain location information from their environment which is used to provide "locally optimal" services. In contrast, it may be of interest to obtain information about the current context a mobile user or device is in, from a client somewhere the Web, i.e. to use the mobile device as an information service provider. As an instance of such services we propose the metaphor of a "location-aware" Web homepage of mobile users providing information about, e.g. the current location a mobile user is at. Requesting this homepage can be as easy as typing a URL containing the mobile user's phone number such as http//mhp.net/+49123456789 in an off-theshelf browser. The homepage is dynamically constructed as Web users access it and it can be configured in various ways controlle...